<!DOCTYPE HTML>
<html>
<head>
<style>
table {
  border-collapse: collapse;
  background-color: red;
}
td, th {
  background-color: lime;
  width:100px;
  height:100px;
  border:4px solid lime;
  box-sizing:border-box;
}
td {
  border-top:hidden;
}
</style>
</head>
<body>
<table cellpadding="0">
  <tr><th colspan="2"></th></tr>
  <tr><th></th><td></td>
</table>
</body>
</html>
